1. Field of the Invention
This invention relates to a continuous process for producing alcohol and is more particularly concerned with a continuous process of producing alcohol through continuous fermentation, solvent extraction, extractive distillation dehydration and vacuum stripping.
2. Description of the Prior Art
The old method of separating alcohols from water uses distillation. Typically, a beer still is used to process the fermented product which contains alcohol in an aqueous mixture and thereby produce an enriched alcohol mixture which is then dried using azeotropic distillation. Solvent extraction processes have been developed earlier, but these systems do not enable the recovery of ethanol which is dry enough to produce gasohol in a single distillation step. My present invention, using extractive distillation dehydration followed by vacuum stripping, appears to be superior to the earlier solvent regeneration techniques in that it reduces the energy requirement further and produces a higher quality product.